How do I choose the right transformer capacity for my project?

Start from measured or estimated load profile instead of summing all nameplate loads directly. Distinguish base load, normal operating load, and short-duration peak load to avoid oversized or undersized selection.

A common engineering approach is to keep a reasonable future margin, often around 15% to 25%, and verify voltage drop and temperature rise under worst-case operating conditions.

If your load includes large motor starts, frequent impact loads, or fast expansion plans, it is better to evaluate with detailed power quality and thermal calculations before finalizing capacity.